Hermaphrodite duck???

Is it possible to have a hermaphrodite duck? We are very puzzled by one of our Muscovies at the moment. He/she is bigger than the girls, but much smaller than the boys. Big feet, hisses like a boy, head shaped like a boy but has girl shaped caruncles. He/she is old enough to be able to visually recognise the sex, but he/she is just so odd! Is there a possibility he/she could really be both?

probably. a female can turn into a male if her ovaries stop functioning right birds have a different sex chromosome set ZZ for male ZW for female so technically all birds are by default male. like mammals are by default female. that's why male humans have nipples because we are all on a female template.